PCSK9 antibody, antigen-binding fragment thereof, and medical application thereof

Abstract

The present invention provides a PCSK9 antibody, an antigen-binding fragment thereof, and a medicinal application thereof. Provided in the invention is a chimeric antibody and a humanized antibody, both comprising a CDR of the PCSK9 antibody, and a pharmaceutical composition comprising the PCSK9 antibody and an antigen-binding fragment thereof, and an application of the PCSK9 antibody as a lipid-lowering agent. The invention specifically relates to an application of a humanized PCSK9 antibody for preparing a pharmaceutical drug to treat a PCSK9-induced disease or symptom.

The invention claimed is: 
     
       1. A PCSK9 antibody or the antigen-binding fragment thereof, wherein the antibody comprises a HCDR1, a HCDR2, and a HCDR3 as shown in SEQ ID NO: 12, SEQ ID NO: 13 and SEQ ID NO: 14, respectively; and
 a LCDR1, a LCDR2, and a LCDR3 as shown in SEQ ID NO: 15, SEQ ID NO: 16 and SEQ ID NO: 17, respectively. 
 
     
     
       2. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 , wherein the PCSK9 antibody or antigen-binding fragment thereof is a murine antibody or fragment thereof. 
     
     
       3. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 , wherein the PCSK9 antibody light chain variable region further comprises light chain FR regions selected from a murine κ chain or murine λ chain; wherein the PCSK9 antibody heavy chain variable region further comprises heavy chain FR regions selected from a murine IgG1, a murine IgG2, or a murine IgG3. 
     
     
       4. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 3 , comprising the heavy chain variable region of SEQ ID NO: 10 and the light chain variable region of SEQ ID NO: 11. 
     
     
       5. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 , wherein the PCSK9 antibody light chain further comprises light chain constant regions selected from a murine κ chain or a murine λ chain; wherein the PCSK9 antibody heavy chain further comprises heavy chain constant regions selected from a murine IgG1, a murine IgG2, or a murine IgG3. 
     
     
       6. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 , wherein the PCSK9 antibody or antigen-binding fragment thereof is a chimeric antibody or fragment thereof. 
     
     
       7. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 , wherein the PCSK9 antibody or antigen-binding fragment thereof is a humanized antibody or fragment thereof. 
     
     
       8. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 7 , wherein the heavy chain FR sequence of the heavy chain variable region of the humanized antibody is selected from a combination sequence of human germline heavy chains IGHV1-2*02 and hjh2; wherein the humanized antibody comprises a FR1, a FR2, a FR3 of human germline heavy chain IGHV1-2*02 and a FR4 of hjh2. 
     
     
       9. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 8 , wherein the humanized antibody contains a heavy chain variable region of SEQ ID NO: 18 or a variant thereof; wherein the variant comprises 1-10 amino acid changes in SEQ ID NO: 18. 
     
     
       10. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 9 , wherein the variant of SEQ ID NO: 18 has 1-9 amino acid back-mutations in the FR regions, wherein the back-mutation is selected from the group consisting of T3ON, R87T, R72A, T74K, M48I, V68A, M7OL, R38K and R67K. 
     
     
       11. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 8 , wherein the humanized antibody contains a heavy chain variable region selected from the group consisting of SEQ ID NO:19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, and SEQ ID NO: 23. 
     
     
       12. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 7 , wherein the light chain FR sequence of the light chain variable region of the humanized antibody is selected from a combination sequence of human germline light chains IGKV1-39*01 and hjk2.1; wherein the humanized antibody comprises a FR1, a FR2, a FR3 of human germline IGKV1-39*01 and a FR4 of hjk2.1. 
     
     
       13. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 12 , wherein the humanized antibody further comprises a light chain variable region as shown in SEQ ID NO: 24 or a variant thereof, wherein the variant comprises 1-10 amino acid changes in SEQ ID NO: 24. 
     
     
       14. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 13 , wherein the variant of SEQ ID NO: 24 has 1-4 amino acid back-mutations in the FR regions, wherein the back-mutation is selected from the group consisting of T5S, S66D, Q3V and A49S. 
     
     
       15. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 12 , wherein the humanized antibody comprises a light chain variable region selected from the group consisting of SEQ ID NO:25, SEQ ID NO: 26, and SEQ ID NO: 27. 
     
     
       16. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 7 , wherein the humanized antibody comprises a heavy chain variable region and/or a light chain variable region, wherein the heavy chain variable region is selected from the group consisting of SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, and SEQ ID NO: 23, or the heavy chain variable region has at least 95% identity to a sequence selected from the group consisting of SEQ ID NO: 19, SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 22, and SEQ ID NO: 23; wherein the light chain variable region is selected from the group consisting of SEQ ID NO: 25, SEQ ID NO: 26, and SEQ ID NO: 27, or the light chain variable region has at least 95% identity to a sequence selected from the group consisting of SEQ ID NO: 25, SEQ ID NO: 26, and SEQ ID NO: 27. 
     
     
       17. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 7 , wherein the PCSK9 antibody comprises a heavy chain variable region and a light chain variable region selected from the group consisting of:
 1) the heavy chain variable region sequence of SEQ ID NO: 18 and the light chain variable region sequence of SEQ ID NO: 25, 
 2) the heavy chain variable region sequence of SEQ ID NO: 18 and the light chain variable region sequence of SEQ ID NO: 26, 
 3) the heavy chain variable region sequence of SEQ ID NO: 18 and the light chain variable region sequence of SEQ ID NO: 27, 
 4) the heavy chain variable region sequence of SEQ ID NO: 19 and the light chain variable region sequence of SEQ ID NO: 24, 
 5) the heavy chain variable region sequence of SEQ ID NO: 19 and the light chain variable region sequence of SEQ ID NO: 25, 
 6) the heavy chain variable region sequence of SEQ ID NO: 19 and the light chain variable region sequence of SEQ ID NO: 26, 
 7) the heavy chain variable region sequence of SEQ ID NO: 19 and the light chain variable region sequence of SEQ ID NO: 27, 
 8) the heavy chain variable region sequence of SEQ ID NO: 20 and the light chain variable region sequence of SEQ ID NO: 24, 
 9) the heavy chain variable region sequence of SEQ ID NO: 20 and the light chain variable region sequence of SEQ ID NO: 25, 
 10) the heavy chain variable region sequence of SEQ ID NO: 20 and the light chain variable region sequence of SEQ ID NO: 26, 
 11) the heavy chain variable region sequence of SEQ ID NO: 20 and the light chain variable region sequence of SEQ ID NO: 27, 
 12) the heavy chain variable region sequence of SEQ ID NO: 21 and the light chain variable region sequence of SEQ ID NO: 24, 
 13) the heavy chain variable region sequence of SEQ ID NO: 21 and the light chain variable region sequence of SEQ ID NO: 25, 
 14) the heavy chain variable region sequence of SEQ ID NO: 21 and the light chain variable region sequence of SEQ ID NO: 26, 
 15) the heavy chain variable region sequence of SEQ ID NO: 21 and the light chain variable region sequence of SEQ ID NO: 27, 
 16) the heavy chain variable region sequence of SEQ ID NO: 22 and the light chain variable region sequence of SEQ ID NO: 24, 
 17) the heavy chain variable region sequence of SEQ ID NO: 22 and the light chain variable region sequence of SEQ ID NO: 25, 
 18) the heavy chain variable region sequence of SEQ ID NO: 22 and the light chain variable region sequence of SEQ ID NO: 26, 
 19) the heavy chain variable region sequence of SEQ ID NO: 22 and the light chain variable region sequence of SEQ ID NO: 27, 
 20) the heavy chain variable region sequence of SEQ ID NO: 23 and the light chain variable region sequence of SEQ ID NO: 24, 
 21) the heavy chain variable region sequence of SEQ ID NO: 23 and the light chain variable region sequence of SEQ ID NO: 25, 
 22) the heavy chain variable region sequence of SEQ ID NO: 23 and the light chain variable region sequence of SEQ ID NO: 26, 
 23) the heavy chain variable region sequence of SEQ ID NO: 23 and the light chain variable region sequence of SEQ ID NO: 27, and 
 24) the heavy chain variable region sequence of SEQ ID NO: 18 and the light chain variable region sequence of SEQ ID NO: 24. 
 
     
     
       18. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 6 , wherein the heavy chain further comprises a heavy chain constant region selected from a human IgG1, IgG2, IgG3, or IgG4;
 wherein the PCSK9 antibody further comprises a light chain constant region selected from a human κ chain or a human λ chain. 
 
     
     
       19. The PCSK9 antibody or the antigen-binding fragment thereof according to  claim 18 , wherein the humanized antibody comprises a heavy chain and a light chain selected the group consisting of:
 1) the heavy chain of SEQ ID NO: 28 and the light chain of SEQ ID NO: 30, and 
 2) the heavy chain of SEQ ID NO: 32 and the light chain of SEQ ID NO: 30. 
 
     
     
       20. A pharmaceutical composition, comprising a therapeutically effective amount of the PCSK9 antibody or the antigen-binging fragment according to  claim 1  and one or more pharmaceutically acceptable carriers, diluents, or excipients. 
     
     
       21. A nucleic acid molecule, encoding the PCSK9 antibody or the antigen-binding fragment thereof according to  claim 1 . 
     
     
       22. An expression vector comprising the nucleic acid molecule according to  claim 21 . 
     
     
       23. An isolated host cell transformed with the expression vector according to  claim 22 , wherein the host cell is selected from the group consisting of a prokaryotic cell and a eukaryotic cell. 
     
     
       24. A method of treating a PCSK9-mediated disease or disorder in a subject in need thereof, comprising administering to the subject the pharmaceutical composition of  claim 20 , wherein the disease or disorder is selected from the group consisting of hypercholesterolemia, heart disease, metabolic syndrome, diabetes, coronary heart disease, strokes, cardiovascular disease, Alzheimer's disease and general Dyslipidemia.